Retro-fit lock kit and method of installing same

ABSTRACT

A retro-fit kit is described for converting a mechanical door lock to an electrically operative door lock. The retro-fit kit features an auxiliary, solenoid controlled belt mechanism which is secured to the back of a door containing a mechanical lock. The locking bolt of the mechanical lock is removed from the door well, and a switch is inserted in its place. The switch is operatively engageable with the retractor of the mechanical lock. The switch is electrically connected between a power source and the solenoid of the electrical bolt mechanism. The electrical bolt mechanism is normally in a closed bolt position, and will assume an open bolt position when there is a power failure, or when the mechanical lock is actuated.

United States Patent [1 1 Salzman et al.

[ Aug. 26, 1975 RETRO-FIT LOCK Kl'l' AND METHOD OF INSTALLING SAME [76] Inventors: Robert Stephen Salzman, 27

Holbrook Dr., Stamford, Conn. 06906; Gerald Martin Goldman, Knollwood Extension, Elmsford, N.Y. 10523 [22] Filed: Oct. 23, 1974 [2|] Appl.No.: 517,165

[52] US. Cl. 292/144; 70/281; 200/44; 200/153 L [5|] lnt. Cl. E05B 47/02 [58] Field of Search 70/277, 280, 281, 282; 292/144, 201

[56] References Cited UNITED STATES PATENTS 3,179,456 4/1965 Schwartz 292/144 Primary ExaminerAlbert G. Craig, Jr.

1 1 ABSTRACT A retro-fit kit is described for converting a mechanical door lock to an electrically operative door lock. The retro-fit kit features an auxiliary, solenoid controlled belt mechanism which is secured to the back ofa door containing a mechanical lock. The locking bolt of the mechanical lock is removed from the door well, and a switch is inserted in its place. The switch is operatively engageable with the retractor of the mechanical lock. The switch is electrically connected between a power source and the solenoid of the electrical bolt mechanism. The electrical bolt mechanism is normally in a closed bolt position, and will assume an open bolt position when there is a power failure, or when the mechanical lock is actuated.

9 Claims, 10 Drawing Figures RETRO-FIT LOCK KIT AND METHOD OF INSTALLING SAME This invention pertains to a retro-fit kit for converting a mechanical door lock to an electrically operative door lock, and more particularly to an electrically operative retro-fitted door lock which will open as a result of a power failure.

RELATED DISCLOSURE This application is related to Disclosure Document No. 033,663, filed on July 10, 1974.

BACKGROUND OF THE INVENTION In 1973, New York City passed local law No. 5, requiring the use of electrical door locks on the Stairways of high rise buildings. The purpose of the law was to prevent people from becoming trapped on the stairways in the event of a fire. The present invention is for a retro-fit kit for converting the mechanical locks already installed in these buildings, to electrical door locks. The purpose of using the retro-fit kit, rather than an original electrical door lock, is to save the realtors installation expense. When one considers the thousands of locks which will be needed to comply with the law, the retro-fit kit will save a substantial sum of money. The retro-fitted electrical lock is designed to fail in the open position. Therefore, if there is a power failure due to a fire or other catastrophe, the lock will open to free the stairways.

SUMMARY OF THE INVENTION The retro fit kit of the invention features attaching an auxilliary, electrically operative bolt mechanism to the door. The locking bolt of the mechanical door lock is removed, and a switch is inserted in the well vacated by the bolt. The switch is placed in engagement with the retractor of the mechanical lock. The electrical bolt mechanism is then electrically connected to the switch.

The electrical bolt mechanism comprises a bolt which is connected to a bell crank. The bell crank is controlled by a solenoid. The solenoid pulls the bell crank to a position over top-dead-center, thus causing a dead-bolt effect to occur. In the actuated condition, the solenoid holds the bolt in a closed position. When the solenoid is deactuated, a spring forces the bell crank to pivot, allowing the bolt to slide to an open position. The solenoid is controlled by the retractor and switch combination, such that the mechanical door lock must be opened, and/or the door knob turned, in order to open the electrical bolt mechanism.

It is an object of this invention to provide an improved method and apparatus for retro-fitting a mechanical door lock to an electrically operative door lock;

It is another object of the invention to provide a failsafe lock, which will fail open when there is a power failure;

It is still another object of this invention to provide a method and lock apparatus for use in stairways of high rise buildings.

These and other objects of the invention will become more apparent and will be better understood, with ref erence to the following detailed description taken in conjunction with the attached drawings, in which:

FIG. I is a perspective view of a heavy duty cylindrical lock disposed within a door, which has been retrofitted to an electrical lock in accordance with the retrofit kit of this invention;

FIG. 2 is an exploded view of the electrical dead-bolt mechanism of the inventive retro-fit kit shown in FIG.

FIG. 3 is an assembled frontal view of the electrical deadbolt mechanism taken along lines 3-3 of FIG. 2, the mechanism is shown in solid line in the operative closed bolt position, and is shown in phantom line in the open bolt position;

FIG. 4 is a top view of the electrical dead-bolt mechanism of FIG. 3, taken along lines 4-4;

FIG. 5 is a top view of the electrical dead-bolt mechanism of FIG. 3, taken along lines 55;

FIG. 6 is a side view of the electrical dead-bolt mechanism of FIG. 5 taken along lines 6-6;

FIG. 7 is a perspective view of the disassembly of the mechanical dead-bolt from the door and the heavy duty cylindrical lock in accordance with the retro-fit shown in FIG. 1;

FIG. 8 is a frontal internal view of the door containing a retractor switch mounted therein in place of the mechanical dead-bolt of FIG. 7, in accordance with the retro-fit kit of FIG. 1;

FIG. 8a is a perspective view of a retractor plate for the retractor switch shown in FIG. 8', and

FIG. 9 is an electrical schematic wiring diagram for the retro-fit kit of FIG. 1.

DETAILED DESCRIPTION Generally speaking, the invention is for a retro-fit kit for converting a mechanical door lock supported by a door, to an electrically operative door lock. The mechanical door lock has a retractor for controlling a locking bolt. The mechanical door lock also comprises at least one rotatively mounted door knob for actuating the retractor. The locking apparatus of the invention comprises switching means disposed in a space in the door vacated by the locking bolt. The switching means is operatively engageable with the retractor, and is operative between a closed circuit position and an open circuit position. An electrically operative bolt mechanism is secured generally to a back portion of the door. The electrically operative bolt mechanism is operatively connected to the switching means, and is operative between a normally closed bolt position, and an open bolt position. The electrically operative bolt mechanism is in the normally closed bolt position when the switching means is in the closed circuit position, and is in the open bolt position, when the switching means is in the open circuit position. Circuit means interconnects the switching means and the electrically operative bolt mechanism.

Now referring to FIG. I, a heavy duty cylindrical lock is shown generally by arrow 10. The cylindrical lock is of the type made by the Schlage Company of San Francisco, California. The cylindrical lock referred to herein, features an outer door knob 11, and an inner door knob I2. The inner knob 12 has a finger switch 14 to lock the knob 12 against rotation. The outer knob 11 will not rotate unless the proper key 15 is inserted in the keyway of the knob (not shown). When either the inner knob 12, or the outer knob 11, are rotated in a clockwise manner as shown by arrows I6 and 17, respectively, a retractor mechanism (not shown) within retractor housing 18 is activated. This retractor mechanism normally causes the mechanical bolt I) generally shown in FIG. 7, to be pulled into the door 20, freeing the door for entry.

However, in order to convert the mechanical lock to an electrical lock in accordance with local law No. 5 (1973) of New York City, it is necessary to remove the mechanical bolt 19 from door 20 as shown by arrow 21 of FIG. 7. The bolt guide plate 22 is also removed with bolt 19.

In place of the mechanical bolt 19, an electrically actuated bolt mechanism shown generally by arrow 23 (FIG. I) is secured to the back of door 20. The electrical dead-bolt mechanism is attached to the back of the door in similar fashion as other ancillary bolt mechanisms, such as Segal locks, are attached.

In the well 24 (FIGS. 7 and 8) left vacant by the bolt 19, a retractor activated switch 25 is placed. This switch 25 controls the electrical bolt mechanism 23. When either knobs 11 or 12 are turned, the teeth 26 of the retractor mechanism are caused to move in direction 27. A pressure plate 28 shown in FIG. 8a is affixed between retractor teeth 26 (FIG. 8). The plate 28 normally abuts against the push button 29 of switch 25, causing button 29 to be depressed. When the retractor teeth 26 move backward (arrow 27), the plate 28 pulls away from button 29, allowing the button to assume a non-depressed position.

The switch 25 is mounted in a cylindrical housing 30 (FIGS. 1 and 8) which fits within well 24. The housing is secured to door 20 by means of a cover plate 31 which fits over flange 33 of the housing. A pair of screws 32 project through the cover plate 31 and the flange 33, into the door 20.

Thus, the housing 30 is anchored into the door and the cover plate 31 is secured to the housing 30. The cover plate 31 is made to fit flush with the edge of the door, by means of the hollow seat 34 left by the removed plate 22 (FIG. 7).

The electrical dead-bolt mechanism 23 of FIG. 1, is housed within a cover 35. A complementary cover 36 is mounted to the door sash 37 by means of two screws 38. The sash cover 36 is a receptical for the bolt 39 of the electrical dead-bolt mechanism 23 as shown in FIGS. 3 through 5. The electrical dead-bolt mechanism 23 will be described with reference to FIGS. 2 through The electrical bolt mechanism 23 comprises a door mounting plate 40 which attaches to the back of the door 20 by means of four screws 41 (FIG. 3). The mounting plate 40 has two flanged sections 42 and 43, respectively, which are bent at 90 from the plate 40 (FIG. 2). Each flanged section 42 and 43, has a respective square aperture 44 and 45 for guiding and securing the square-shaped bolt 39 for sliding movement. A third flanged plate section 46 is also bent at 90 from plate 40. The flanged section 46 contains a laterally extending pin 47. The pin 47 seats within hole 48 in cover plate 35 (FIGS. 3-5). Pin 47 is a locating pin for mount ing the cover plate 35 to door plate 40. Cover plate 35 is secured to door plate 40 by means of two screws 49, which project through flange section 43 and screw into screw holes 50 disposed in sockets 51 of the cover 35.

A continuous duty solenoid 52 is mounted to plate 40 by two screws 53 (FIG. 4). The pull-rod 54 of the solenoid (FIGS. 2 and 3) is pivotably attached to one end of a solenoid link 55 via pin 62. The other end of link 55 is pivotably secured to the long arm of a bell crank member 56 by means of a slotted pin 57 and a C clamp 58. The short arm of the bell crank member 56 is pivotably mounted to one end of bolt link 59 by means of a slotted pin 60 and a C clamp 61. The link 59 is pivotably mounted within slot 74 of bolt 39 by means of pin 63.

The bell crank 56 is pivotably secured to shaft 64 via slotted pin 66 and C clamp 65. The shaft 64 is affixed to plate 40 as shown in FIG. 2. A torsion spring 67 is wrapped about shaft 64. One arm 68 of the spring abuts flanged section 46. and the other arm 69 has a digit 70 which fits into groove 71 in bell crank 56. Torsion spring 67 biases the bell crank 56 in a counterclockwise direction 72 (FIG. 3).

OPERATION OF THE INVENTION Operation of the retro-fitted lock will be described in conjunction with the electrical schematic of FIG. 9. A power transformer 73 supplies power to the solenoid 52 of the dead-bolt mechanism 23. The solenoid 52 is normally continuously on. The switch 25 is disposed in bolt well 24 is a normally open switch, whose button is normally depressed to provide a closed circuit between the solenoid 52 and the power transformer 52. A smoke or fire detector 75 and a door jam switch 76 may also be connected in the line between the transformer 73 and the solenoid 52. In case of a fire, the smoke detector 75 will break the circuit, and power will not be supplied to the solenoid 52. The door jam switch 76 will detect when the door 20 is seated properly against the sash 37 (FIG. I). This switch will only provide a closed circuit when the door and sash are aligned. This assures that the solenoid will not get power unless the door is aligned so that the bolt 39 will be in a position to seat within cover 36. The door jam switch 76 can be mounted anywhere on the edge of the door or sash, but may be conveniently mounted on flanged section 43 (FIG. 2).

When the door is closed, the bolt 39 will normally be seated in the cover 36 as shown in FIGS. 3-5. The solenoid 52 will be on, and the pull rod 54 will be seated in the home position (as shown in solid lines in FIG. 3). In this position, the bell crank 56 will be pivoted against the biasing force (arrow 72) of the spring 67. This will cause the link 59 to assume a position over topdeadcenter, thus causing a dead-bolt effect for bolt 39. In other words, bolt 39 cannot be manually forced backwards (arrow 77), when the pull-rod S4 is seated within solenoid 52.

When the power is deprived to the solenoid 52, the spring 67 will cause the bell crank 56 to pivot in direction 72 (FIG. 3), and the mechanism will obtain the open position shown by the phantom lines of FIG. 3. The bolt 39 will move out of the cover 36, thus freeing the door 20 for entry.

Power will be interrupted to solenoid 52 only under the following conditions:

A. When either knob 11 or knob 12 (FIG. I) are totated (arrows 17 or 16, respectively), switch 25 (FIG. 8) will be caused to open as shown in FIG. 9. This will occur when the right key is inserted in outer knob 11, or when finger switch 14 is opened from inside knob 12;

B. When smoke or fire detector switch 75 detects a fire and opens the circuit of FIG. 9;

C. When the door 20 is not aligned with the sash 37, the circuit of FIG. 9 will remain open; and

D. When there is a power failure due to a tire, or other condition, power will be interrupted from transformer 73 to solenoid 52.

It will be obvious from the foregoing discussion, that a retro-fit kit for converting a mechanical door lock to an electrical door lock has been shown. The retro-fit kit, allows for a minimum of expense and maintenance in complying with local law No. 5 1973) of New York City. While the heavy duty cylindrical lock has been described as one manufactured by the Schlage Company, other similar door locks can be retro-fitted, such as that manufactured by P. and F. Corbin, Division of Emhart Corp., Connecticut. The Corbin lock has a single-toothed retractor, rather than a two-tooth retractor 26 of the Schlage lock. In such a case, the retractor plate 28 of FIGS. 8 and 8a is not necessary, since the button of switch will be easily depressed by the Corbin retractor.

Naturally, other electrical bolt mechanisms can be designed and fitted as ancillary locking devices, as befits those skilled in the art.

A buzzer can be connected into the circuit of FIG. 9, to signal when the door is in the unseated condition, or when the solenoid does not receive any power.

All modifications and changes of an obvious nature to those skilled practitioners in this art are deemed to fall within the spirit and scope of this invention as represented by the appended claims.

What is claimed is:

l. in a retro-fit kit for converting a mechanical door lock supported by a door, to an electrically operative door lock, said mechanical door lock having a retractor for controlling a locking bolt, and at least one mounted door knob for actuating said retractor, a locking apparatus comprising:

switching means disposed in a space in said door vacated by said locking bolt and operatively engageable with said retractor, said switching means being operative between a closed circuit position and an alternate open circuit position;

an electrically operative bolt mechanism secured generally to a back portion of the door and operatively connected to said switching means, said electrically operative bolt mechanism being operative between a normally closed bolt position and an open bolt position, said electrically operative bolt mechanism being in the normally closed bolt position when said switching means is in one circuit position, and being in an open bolt position when said switching means is in the alternate circuit position; and

interconnecting means for interconnecting said switching means and said electrically operative bolt mechanism.

2. The locking apparatus of claim 1, wherein said electrically operative bolt mechanism comprises a dead-bolt device.

3. The locking apparatus of claim 2, wherein said dead-bolt device comprises a pivotably mounted bell crank, a solenoid, and a slidable bolt, said bolt being connected to said bell crank, and said bell crank being operatively controlled by said solenoid, said bolt being in a dead-bolt position when said bell crank has been pivoted past a top-dead-center position.

4. The locking mechanism of claim 3, wherein said bell crank is spring biased toward an open bolt position.

5. The locking apparatus of claim 1, wherein said switching means comprises a normally open switch that is normally in the operative closed circuit position.

6. The locking apparatus of claim 1, wherein said interconnecting means comprises a smoke detector.

7. The locking apparatus of claim I, wherein said interconnecting means comprises a door jam switching means.

8. The locking apparatus of claim 1, wherein said interconnecting means comprises a tire detector.

9. In a retro-fit kit for converting a mechanical door lock supported by a door, to an electrically operative door lock, said mechanical door lock having a retractor for controlling a locking bolt, and at least one rotatively mounted door knob for actuating said retractor, a method of converting said mechanical door lock to said electrically operative door lock, comprising the steps of:

a. removing said locking bolt from a well in said door;

b. inserting a switch in the well vacated by said locking bolt;

c. placing said switch in operative engagement with said retractor;

d. securing an electrically operative bolt mechanism to the door; and

e. electrically connecting the electrically operative bolt mechanism to said switch. 

1. In a retro-fit kit for convertinG a mechanical door lock supported by a door, to an electrically operative door lock, said mechanical door lock having a retractor for controlling a locking bolt, and at least one mounted door knob for actuating said retractor, a locking apparatus comprising: switching means disposed in a space in said door vacated by said locking bolt and operatively engageable with said retractor, said switching means being operative between a closed circuit position and an alternate open circuit position; an electrically operative bolt mechanism secured generally to a back portion of the door and operatively connected to said switching means, said electrically operative bolt mechanism being operative between a normally closed bolt position and an open bolt position, said electrically operative bolt mechanism being in the normally closed bolt position when said switching means is in one circuit position, and being in an open bolt position when said switching means is in the alternate circuit position; and interconnecting means for interconnecting said switching means and said electrically operative bolt mechanism.
 2. The locking apparatus of claim 1, wherein said electrically operative bolt mechanism comprises a dead-bolt device.
 3. The locking apparatus of claim 2, wherein said dead-bolt device comprises a pivotably mounted bell crank, a solenoid, and a slidable bolt, said bolt being connected to said bell crank, and said bell crank being operatively controlled by said solenoid, said bolt being in a dead-bolt position when said bell crank has been pivoted past a top-dead-center position.
 4. The locking mechanism of claim 3, wherein said bell crank is spring biased toward an open bolt position.
 5. The locking apparatus of claim 1, wherein said switching means comprises a normally open switch that is normally in the operative closed circuit position.
 6. The locking apparatus of claim 1, wherein said interconnecting means comprises a smoke detector.
 7. The locking apparatus of claim 1, wherein said interconnecting means comprises a door jam switching means.
 8. The locking apparatus of claim 1, wherein said interconnecting means comprises a fire detector.
 9. In a retro-fit kit for converting a mechanical door lock supported by a door, to an electrically operative door lock, said mechanical door lock having a retractor for controlling a locking bolt, and at least one rotatively mounted door knob for actuating said retractor, a method of converting said mechanical door lock to said electrically operative door lock, comprising the steps of: a. removing said locking bolt from a well in said door; b. inserting a switch in the well vacated by said locking bolt; c. placing said switch in operative engagement with said retractor; d. securing an electrically operative bolt mechanism to the door; and e. electrically connecting the electrically operative bolt mechanism to said switch. 